Linked Life Data

15219696

Source:http://linkedlifedata.com/resource/pubmed/id/15219696

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
2004-6-28
pubmed:abstractText
By combining electron tomography with energy-filtered electron microscopy, we have shown the feasibility of determining the three-dimensional distributions of phosphorus in biological specimens. Thin sections of the nematode, Caenorhabditis elegans were prepared by high-pressure freezing, freeze-substitution and plastic embedding. Images were recorded at energy losses above and below the phosphorus L2,3 edge using a post-column imaging filter operating at a beam energy of 120 keV. The unstained specimens exhibited minimal contrast in bright-field images. After it was determined that the specimen was sufficiently thin to allow two-window ratio imaging of phosphorus, pairs of pre-edge and post-edge images were acquired in series over a tilt range of +/-55 degrees at 5 degrees increments for two orthogonal tilt axes. The projected phosphorus distributions were aligned using the pre-edge images that contained inelastic contrast from colloidal gold particles deposited on the specimen surface. A reconstruction and surface rendering of the phosphorus distribution clearly revealed features 15-20 nm in diameter, which were identified as ribosomes distributed along the stacked membranes of endoplasmic reticulum and in the cytoplasm. The sensitivity of the technique was estimated at < 35 phosphorus atoms per voxel based on the known total ribosomal phosphorus content of approximately 7000 atoms. Although a high electron dose of approximately 10(7)e/nm2 was required to record two-axis tilt series, specimens were sufficiently stable to allow image alignment and tomographic reconstruction.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0304-3991
pubmed:author
pubmed:copyrightInfo
Copyright 2004 Elsevier B.V.
pubmed:issnType
Print
pubmed:volume
100
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
115-25
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Three-dimensional distributions of elements in biological samples by energy-filtered electron tomography.
pubmed:affiliation
Division of Bioengineering and Physical Science, ORS, National Institutes of Health, Building 13, 3N17, Bethesda, MD 20892, USA. leapman@helix.nih.gov
pubmed:publicationType
Journal Article, Comparative Study